Atari 810 Disk Drive Field Service Manual Rev 1

NOTICE

To All Persons Receiving This Document

CONFIDENTIAL INFORMATION

Reproduction is forbidden without the specific
written permission of ATARI, INC., Sunnyvale, CA
94086. No right to reproduce this document, nor
the subject matter thereof, is granted unless by
written agreement with, or written permission from
the Corporation.

ATARI 810 DISK DRIVE

FIELD SERVICE MANUAL

JULY 1980
FS015854
REV. 1

TABLE OF CONTENTS

1. SPECIFICATIONS 1_1

2. THEORY OF OPERATION 2-1

3. BLOCK DIAGRAMS & SCHEMATICS 3-1

4. FLOPPY QUICKCHECK 4-1

5. TROUBLESHOOTING GUIDE 5-1

6. DISASSEMBLY/REASSEMBLY 6-1

7. ADJUSTMENTS 7_1

8. PARTS LISTS 8-1

9. APPENDIX 9_;L

10. INDEX 10 _ x

SPECIFICATIONS

TECHNICAL SPECIFICATIONS

1 .

2 .

3.

4.

5.

6 .

7.

8 .

9.

10 .

Uses ANSI standard 5h inch diskettes in a
soft sectored format.

40 tracks at 48 TPI track density.

Single density (FM) , single sided recording.

Over 90K bytes storage per diskette.

709 sectors of 128 bytes each.

Minimum data access time: 236 milliseconds.

Average data transfer rate: 6000 bits per second.
Automatic stand-by capability (built in
microprocessor) .

Up to four Drives can be daisy chained to a single
400/800 Computer Console (w/minimum 16K RAM)
via select switches at the rear of the Drive.
Drives directly interface with the ATARI 400/800
Computer Console (16K RAM) or indirectly through
the ATARI 850 Interface Module or 820 Printer.

1-3

1-4

THEORY OF OPERATION

2-2

THEORY OF OPERATION

The ATARI 400/800 Computer Console with 16K of RAM
installed connects directly to the 810 Floppy Disk
Drive. The Drive may also be daisy chained through
the 820 Printer or the 850 Interface Module. Up to
four Disk Drives can be connected to a single Console.

Refer to the Disk Drive Operators Manual for instal-
lation and operating instructions.

2-3

ATARI 810 FLOPPY
DISK DRIVE

The ATARI 810 Floppy Disk Drive consists of the
following major sections:

* Data Input/Output and Manipulation

* Data Interface

* Read/Write and Erase Heads

* Stepper Motor and Logic

* Diskette Drive Motor and Logic

* Power Supply

2-4

DATA INPUT/OUTPUT AND MANIPULATION SECTION

TO AND FROM
COMPUTER CONSOLE

DATA INPUT/OUTPUT AND MANIPULATION SECTION

Data, control commands and a VCC/RDY signal from the
Computer Console enter the Disk Drive through either
of the two serial I/O connector jacks at the rear of
the Drive chassis.

Each of the three main signal input lines are buffered
for static protection and to reduce power consumption
on the 800 I/O lines.

Data is sent by the Console in serial format, with
checksums accompanying the data for validity verification.

2-5

PIA

TO STEPPER
MOTOR LOGIC

TO OISKETTE DRIVE
MOTOR LOGIC

L — I Vcc / ROY U.
1 aUFFER ~

DAT)

BT"

l

POWER

np

fwi

LOGIC

;

DATA OUT BUFFER |—

TO AND FROM
DATA INTERFACE
SECTION

(STATUS INFO)
(RESET)

DATA (OUT) z|

in

TO AND FROM
COMPUTER CONSOLE

DATA INPUT/OUTPUT AND MANIPULATION SECTION

The Drive's PIA is primarily a buffering and signal
formatting device, with no decision making or compu-
tational capability. It is responsible for the
following:

* Applying the Console's serial outputs to the
Data and Address Busses when requested by the
Drive's Microprocessor Unit (MPU) .

* Assisting in the control of the Read/Write
and Erase Head position by buffering commands
sent to the Stepper Motor Logic.

* Assisting in control of the Diskette Drive
Motor Logic.

* Providing 128 bytes of RAM for temporary
storage of status information and data sent by
the Data Interface Section for application

to the MPU.

2-6

TO AND FROM
COMPUTER CONSOLE

DATA INPUT/OUTPUT AND MANIPULATION SECTION

The MPU provides the primary decision making and
computational capabilities for the Disk Drive. The
Drive's MPU is responsible for the following:

* Controlling data transfers, through its
control over the Common Data and Address
Busses .

* Interpreting and controlling the accomplishment
of Console commands (temporarily stored

in RAM) and Disk Drive operating instructions
(permanently stored in ROM) .

* Controlling the Stepper, Disk Drive and Motor
Logics, which are buffered by the PIA.

The Drive's ROM contains specific operating instructions
used by the CPU to accomplish a variety of functions.
These functions include telling the Disk controller
(1771-01) what task to perform.

The Drive's RAM is used by the CPU for temporary storage
of both data and system information.

2-7

DATA INPUT/OUTPUT AND MANIPULATION SECTION

TO ANO from
COMPUTER CONSOLE

The Drive's Data Output Buffer transfers the
formatted data through the PIA to the Data (out)
line going to the Computer Console.

2-8

TO AND FROM
DATA INTERFACE
SECTION

(STATUS INFO)

TO DISKETTE DRIVE
MOTOR LOGIC

TO AND FROM
COMPUTER CONSOLE

DATA INPUT/OUTPUT AND MANIPULATION SECTION

The Drive's Power Up Logic circuit resets the MPU,

PIA and Data Interface Section whenever the Disk Drive
is turned on. The RESET references the electrical
circuits to their starting conditions. Additionally,
the Power Up Logic circuit locks the Data Output
Buffer off during a short period when the Drive is
turned on. This prevents random pulses generated by
the Drive's circuitry (during the initializing period)
from being sent to the Console.

The Drive's Clock circuitry generates both a crystal
contolled 1 MHz. and a 500 KHz. clock signal. The
1 MHz. signal is used by the Data Interface Section.

The 500 KHz. signal is used both as a clock signal to
the MPU, and to time data exiting from the Data Input/
Output and Manipulation Section into the Data Interface
Section.

2-9

DATA INTERFACE SECTION

The major element of the Data Interface Section is a
Floppy Disk Controller (FDC) . The FDC is a highly
specialized microprocessor. It is responsible for
the following activities:

* Combining data, timing and data validity
pulses into the serial format to be recorded.

* Separating the above and providing the output
data in parallel during a read operation.

* Controlling the Write and Erase Logic circuitry
during a write operation.

2-10

* Generating the data validity codes (called
Cyclic Redundancy Checks - or CRC's) during a
write operation, and checking them during a
read operation.

DATA INTERFACE SECTION

The Drive's Write and Erase Logic circuitry is controlled
by, and receives its data from the FDC . Initially, the
Data Gate converts the leading edge of each pulse
( < 3- a ta, clock, etc.) into a single corresponding change
of signed level. These levels then determine the polarity
of the Drive's currents applied to the Read/Write Head
through the High and Low level Drives. The Write Driver
limits the write currents.

2-11

clock d&ta i clock oata o clock data i The FDC combines clock pulses with

data to form a serial signal.

The Data Gate converts each pulse’s
leading edge into a logic level
change, as shown.

Basically, this is the signal applied to the head during a write
operation. The high levels out of the Data Gate turn on the High
level Driver, and the low levels turn on the Low level Driver.

DATA INTERFACE SECTION

The Write and Erase Gate turns on both the Write and
Erase Drivers during a write operation, and turns them
off during a read operation. The Erase Driver drives
the Erase Head during a write operation . See the Read/
Write and Erase Head discussion for further information

2-12

CLOCK
( I MHz)

DATA INTERFACE SECTION

Major elements of the Drive's Read Data Conditioning
circuitry are:

* Differential Amp - Initial amplification of
Read/Write Head signals.

* Differentiator - Squaring up the two differ-
ential amp outputs.

* Zero Crossing Detector - The single output
changes level whenever the two 180° out-of-
phase input signals cross their zero axis
coincidentally (eliminates false pulses caused
by Read/Write Head signal decay, rather than
intentional signal level changes) .

* Symmetry Amp - Ensures exact zero referencing of
the signal.

* Time Domain Filter - Trims and further shapes
the signal.

* Signal Gate - Produces a single pulse out for each
logic level transition at its input. This results
in the reproduction of the original FDC signal.

2-13

During a read operation the Read/Write Head produces
two 180° out-of-phase signals. These are very weak,
highly distorted versions of the original signals pro-
duced by the Write Logic Data Gate. The Read Data
Conditioning circuitry must amplify, square up and
filter the read signals to reproduce the original
serial string of bits produced by the FDC . This re-
produced signal is returned to the FDC by the Read
Data Conditioning circuitry.

PULSE

TIME

REGEN-

4 "

DOMAIN

ERATOR

FILTER

n

SYMMETRY

n

AMP

2-14

WRITE

PROTECT

r*<

WRITE ANO
ERASE
GATE

SYMMETRY

AMP

ZERO

CROSSING

DETECTOR

DIFFERENTIATOR

DIFFERENTIAL

AMP

REAO/ WRITE
HEAD

Two 180 out— of —phase signals are
generated by the head during a read
operation and amplified by the
Differential Amplifier,

The Differentiator squares the two
out-of -phase signals.

The Zero Axis Crossing Detector
provides a single output, further
squared and now without any signal
decay effects.

The Time Domain Filter provides a
signal with very sharp leading and
trailing edges.

The Pulse Regenerator converts each
logic level change into a single puls
recreating the original signal produc
by the FDC during the write operation

CLOCK
( I MHz)

WRITE

PROTECT

u

PULSE

REGEN-

w m

ERATOR

pH

■

KHiH

Hk jBBa& M

| ERASE |

II

i

■

READ/ WRITE
HEAD

r

n

data interface section

The Drive's Write Protect circuit senses the presence
or absence of a special notch in one side of the diskette
casing. A write protected diskette's notch will be
covered with an opaque tape. The circuit is basically
an LED/photo transistor sensor, whose output is buf-
fered before being applied to the FDC.

With an unprotected diskette, the sensor signal allows
the FDC to write data onto the diskette.

2-16

CONTROL
LINES FROM PIA

9-10 VAC

STEPPER MOTOR AND LOGIC

The Stepper Motor is a four phase motor with a 3.6°
rotor rotation per step. The motor has a total of 100
poles, providing 100 rotor steps for the motor's full
360° rotation. Each step change in the motor is translated,
through a steel band connection, to a single track
change for the Read/Write and Record Head assembly. The
diskette is divided into 40 tracks, so the full range
of the Stepper Motor is not used.

The Stepper Logic is controlled from the PIA. The four
PIA signals are logic levels acting as the Stepper
Motor's four phase inputs. These levels, in their
various possible combinations, drive the Stepper Motor to
reposition the head assembly from track to track.

The Stepper Motor is supplied with a nominal 9 to 10 VAC
from the Power Supply.

2-17

DISKETTE DRIVE MOTOR AND LOGIC

The Diskette Drive Motor is a DC motor that indirectly
drives the diskette. The motor includes an internal
tachometer, whose output is monitored in the Tach Feed-
back circuit. Variations in motor speed, as sensed by
the Tach Feedback circuit, vary the current supplied
to the motor. Diskette speed is set to 290 RPM ±1%.

Motor rotation is translated into diskette rotation
via a pulley (attached to the motor shaft) , a drive
belt and a flywheel attached to a diskette drive spindle.

When a diskette has been inserted into the Disk Drive,
and the front door has been latched closed, the diskette
is centered and clamped to the spindle by a clutching
cone assembly.

Whenever the Diskette Drive Motor is supplied with power,
the Drive's BUSY lite (LED) is turned on.

2-18

DISK DRIVE SELECT

□RIVE CODE NO.

NO. 1 NO. 2

PWR.

0 •©
NO. 3 NO. 4

A double "Single pole — Double throw" switch gives
the Disk Drive operator the ability to assign a number
to, and therefore a code for addressing, each of up
to four Drives that could be daisy chained together.
The switch is accessible at the rear of the Drive
chassis. The switch settings are read by the Drive's
MPU through the PIA.

2-19

+I2V,

DC (REG)

120

VAC

POWER SUPPLY

An external step-down transformer is supplied with each
Drive. The 120 VAC line power is dropped to 9 VAC by
the transformer. This 9 VAC enters the Drive through the
"PWR" jack at the back of the chassis.

Turning the Drive's front panel "PWR" switch ON applies
the 9 VAC to a full wave bridge rectifier. The Power
Supply provides the following:

* The unregulated 9-10 VDC Diskette Drive Motor
supply.

* A regulated +5 VDC.

* A regulated +12 VDC (initially produced by a
voltage doubler circuit) .

* A zener regulated -5 VDC (also produced by a
voltage doubler circuit) .

A PWR ON" lite (LED) is turned on through the -5 VDC
section of the supply.

2-20

READ/WRITE AND ERASE HEADS

A magnetic head converts electrical currents into
magnetic fields, and vice-versa. The Read/Write
Head consists primarily of two ferrite core halves,
wound with a centertapped coil. The centertap is
connected to the regulated +5 VDC from the Power
Supply. One end of the coil is connected to the
High level Driver, and the other end to the Low
level Driver.

WRITE OPERATION

Each logic level causes current to flow in one half
of the coil, with a high in one direction and a low
in the other. These currents set up corresponding
magnetic fields in the core halves, with a high rep-
resented by a field in one direction, and a low by
a field in the opposite direction.

When the ferric oxide coating on the diskette is in
contact with the head, it completes the magnetic path
between the core halves. In response to the change
in direction of the magnetic field (logic level change)
passing through the diskette's coating, the oxide
particles realign themselves. Particle alignment in
one direction represents a high level, and alignment
in the other direction a low level.

2-21

TRACK 15

ERASE HEAD SAPS

TRACK)

READ/ WRITE
HEAD SAP
. 013"

.036"

TRACK 13 y,

-N— -1 Ration

During a write operation, the magnetic fields coupling
through the diskette print a relatively wide (.013") path
aligned particles. In order to prevent one recorded
track from interfering with either the next inner or next
outer track, a blank space, called a guardband, is created
between tracks. The Erase Head creates these guardbands.
It straddles the Read/Write Head in such a way that just
after (.036") the data is written onto the diskette, the
Erase Head "tunnel" erases the track width down to .012",
leaving .008" guardbands between tracks.

READ OPERATION

During a read operation, the very small fields existing
due to particle alignment on the diskette couple through
the head core halves. The diskette is rotating, causing
the specific field being felt in the core halves to change
for each change in particle alignment (ie. change of re-
corded logic level) . The changing fields in the core
halves generate corresponding currents in the head coil
windings. It is these very small signals that are applied
to the differential amplifier.

2-22

DISKETTE FORMATTING

The specific arrangement of information recorded onto
a diskette is called the diskette format. Unless a
Master Diskette is to be used, the diskette must be
initially formatted with a Disk Operating System (DOS)
software program.

The DOS software divides the diskette into 19 pie-shaped
slices, 18 of which are called sectors. These are not
the same as the "709 FREE SECTORS" referred to when
you list the directory of a disk. Because the diskette
division is accomplished totally through software, this
process is called "soft sectoring". The 18 sectors are
equal in size, but the 19th (very narrow) slice acts as
an index to define the start of each of the 40 tracks.

2-23

All 40 tracks receive the same formatting as follows:

2-24

**

| — 256

bytes

00

1

byte

FC (index mark)

- 11

bytes

00 or FF

“ 6

bytes

00

1

byte

FE

1

byte

Track Number (00 thru 27)

1

byte

00

1

byte

Sector Number (01 thru 12

1

byte

00

1

byte

CRC byte 2

1

byte

CRC byte 1

17

bytes

00

or

11

bytes

FF

6

bytes

00

1

byte

FB (data address mark)

128

bytes

Data (FF for blank fill)

1

byte

CRC byte 2

1

byte

CRC byte 1

— 11

bytes

00 or FF

Cyclic Redundancy Checks (CRCs) are generated in the
Drive's Floppy Disk Controller (FDC) during a write
operation. The FDC uses the recorded CRCs during a
read operation to verify the data. CRCs are similar
in function to the checksums used between the Computer
Console and the Disk Drive's MPU.

Appear only once per track for indexing.
Repeated 18 times per track, producing the
full 18 sectors.

2-25

2-26

BLOCK DIAGRAMS

AND

SCHEMATICS

On the following pages are block diagrams and
schematics for the Disk Drive. Further understanding
of the system* s operation can be obtained by comparing
these.

3-1

3-2

3-3

CO 14334 CD40I3

3-6

DRIVE MOTOR 1 J 103 | C ON NECTOR TO SIDE BOARD I j|06

3-7

3-8

FLOPPY QUICKCHECK

4-2

This procedure should be completed both as a
pre-service checkout and a final (post-service)
checkout for the Disk Drive.

As a pre-service checkout, it will assist in identifying
problems in the Drive.

As a final checkout, it will ensure that all repairs
and alignments were successfully completed.

This procedure follows this flow chart:

All tests must be completed in the sequence shown.

4-3

The following are required to perforin these
procedures :

A. Atari 400/800 Computer Console with a

BASIC cartridge and minimum 16K RAM installed.

B. I/O cables and Console/Drive power packs.

C. TV.

D. Master Disk File Manager diskette with write
protect notch taped.

E. Blank scratch diskette (not write-protected).

F . Prerecorded sample diskette with DOS and
sample programs recorded on a known "good”

Disk Drive.

SETUP

1. Connect the Drive to the Console, and connect
both to power.

2. Turn the Drive ON and wait for the BUSY lite to

go off. if BUSY lite does not come on and then go off,
recheck connections, then refer to the Troubleshooting .
Guide.

BOOTING TEST

1. Insert a Master Disk File Manager diskette into
the Drive and close the Drive's door.

2. Turn the Console OFF, then ON. Verify that data
is transferred from the diskette to the Console
RAM (turn up the TV sound and listen for the
"buzz .. .buzz ... buzz ... etc . " , this should take
about 10 seconds) . When completed, the TV screen
should display the word READY.

3 • If the TV displays any ERRORS or does not show
READY very shortly, repeat step 2. If the
system still will not "BOOT UP", recheck your

4-4

Console/Drive system and hookup for misconnections
or gross equipment failures. If none are found and the
system continues to ERROR, refer to the Troubleshooting
Guide in this manual.

4. When the system has booted,

a. type DOS (Disk Operating System)

b. press' the RETURN key

5. Verify that the DOS menu appears on the TV screen.

Refer to the Troubleshooting Guide if you encounter
an ERROR on the TV screen.

WRITE PROTECT TEST

This test must be completed with the write-protect*-
ed Master diskette installed. The TV screen should
be displaying the DOS menu from the Booting Test.

1. At the Console:

a. type I (capital letter)

b. press RETURN

c. type 1 (number one)

d. press RETURN

e . type Y

f. press RETURN

2. Verify that the TV screen displays ERROR-144.

If it does, the write protect circuit is operating
correctly, go on to Step 3. If it does not;

a. Repeat Step 1 again.

b. If the ERROR-144 still does not appear,
refer to the Troubleshooting Guide.

4-5

3. Remove the Master diskette from the Drive.

FORMATTING TEST

CAUTION: The formatting operation erases the contents

of a di ske t te .

This test must be completed with the DOS from the
Master diskette still stored in the Console RAM.

1. Insert a non-write-protected scratch diskette into

the

Drive and close

the door

At

the Console:

a.

press SYSTEM RESET

b.

type DOS

c.

press RETURN

d.

type I (capital

letter)

e.

press RETURN

f .

type 1 (number one)

g-

press RETURN

h.

type Y

i .

press RETURN

3. Verify that after about 45 seconds of formatting the
Drive's BUSY lite turns OFF and no ERRORS have been
displayed on the TV screen (refer to the Trouble-
shooting Guide for any ERRORS) .

4. At the Console:

a. type A

b. press RETURN

c. press RETURN

5. Verify that "709" or "FREE SECTORS 709" is displayed

at bottom of screen. If not, refer to the Troubleshooting
Guide.

6* Press RETURN to get back to "MENU"

4-6

WRITE VERIFICATION

This test must immediately follow the FORMATTING TEST.

1. At the Console.:

a. type H

b. press RETURN

c . type Y

d. press RETURN

2. Verify that the TV screen displays SELECT ITEM
after a short period of time. If it does not,
refer to the Troubleshooting Guide.

3. At the Console:

a. type A

b. press RETURN

c. press RETURN

4. Verify that the TV screen displays DOS SYS
and number of sectors used, followed by the
number of sectors remaining. . If it does not,
repeat the procedure. If the second attempt fails,
refer to the Troubleshooting Guide.

4-7

5. Delete the file as follows:

a. At the Console:

1. press RETURN

2. type D

_3 . press RETURN
4. type DOS. SYS
_5. press RETURN
6.. type Y

press RETURN

b. After a "SELECT ITEM" appears, at the Console:

1. type A

2. press RETURN

3. press RETURN

c. Verify that the TV screen indicates that there are
709 free sectors remaining.

6. Remove the blank scratch diskette from the Drive.

4-8

COMPATABILITY TEST

This test verifies that the Drive can read
programs from a diskette recorded on a known
"good" Drive.

1. Insert a sample diskette into the Drive.

2. Turn the Console OFF, then ON.

3. Verify that after about 10 seconds, the TV
screen displays READY.

4. At the Console:

a. type DOS

b. press RETURN

5. Verify that the DOS menu appears on the TV
screen, indicating that the diskette data was
correctly loaded into the Console RAM. Refer

to the Troubleshooting Guide in case of any ERRORS.

6. At the Console:

a. type A

b. press RETURN

c. press RETURN

7. Verify that the Drive's BUSY lite comes ON
as the Drive loads its directory listing

into the Console. The directory should appear
on the TV screen.

8. Choose a program you wish to load.

At the Console:

a. press RETURN

b. type B

c. press RETURN

d. type LOAD " D : NAME OF PROGRAM"

e. press RETURN

9 .

Verify that the Drive's BUSY lite comes on
as the Drive loads the selected program. After
several seconds , the word READY should appear at
the top of the screen. If not, refer to the
Troubleshooting Guide.

10. At the Console:

a . type RUN

b. press RETURN

Verify that the selected program runs correctly.
If it ERRORS, refer to the Troubleshooting Guide.

4-10

5-1

5-2

SYMPTOM

POSSIBLE CAUSE

BSnV'-— - - -

I CORRECTIVE ACTION

1. DRIVE WILL NOT

A. DEFECTIVE TRANSFORMER

A. REPLACE TRANSFORMER

TURN ON

B. ELECTRICAL MALFUNC-

B. REPLACE AND/OR

TION - POWER SWITCH/

TROUBLESHOOT PCB(S)

SIDE PCB, POWER SUP-

PLY/REAR PCB

2. DRIVE WILL NOT

A. DEFECTIVE SIDE AND/

A. REPLACE OR REPAIR

TURN OFF

OR REAR PCB

PCBS

3. DISKETTE DOES

A. DRIVE BELT HAS FALLEN

A. REPOSITION OR REPLACE

NOT TURN

OFF FLYWHEEL/PULLEY

DRIVE BELT

OR IS BROKEN

B. DRIVE MOTOR DEFECT-

B. REPLACE DRIVE MOTOR

IVE

C. CLUTCH CONE NOT

C. ADJUST OR REPLACE

CLAMPING DISKETTE

CLUTCH CONE ASSEMBLY

D. ELECTRICAL MALFUNC-

D. REPLACE AND/OR

TION - DRIVE MOTOR

TROUBLESHOOT PCB

CIRCUIT, REAR PCB

5-3

4. DISKETTE SPEED
SLOW OR VARY-
ING

A. DRIVE MOTOR TACH
LINE OUT OF PLACE

B. WRITE PROTECT
CIRCUIT BAD

C. DRIVE BELT INCOR-
RECTLY TENSIONED

D. DRIVE BELT STRETCHED

E. ELECTRICAL MALFUNC-
TION - DRIVE MOTOR
CIRCUIT, REAR PCB

F. SPINDLE BEARINGS
FREEZING

A. CONNECT GREEN MOTOR
HARNESS LEAD TO CENTER
TERMINAL OF WRITE
PROTECT HARNESS

B. REPLACE TRANSPORT LEFT
SIDEPLATE

C. ADJUST DRIVE BELT
TENSION

D. REPLACE DRIVE BELT

E. REPLACE AND/OR
TROUBLESHOOT PCB

F. REPLACE SPINDLE
BEARINGS

5. DISKETTE WON’T
EJECT WHEN FRONT
DOOR IS OPENED

A. EJECT MECHANISM
NEEDS ADJUSTING OR
IS BROKEN

B. CLUTCH CONE-TO-
SPINDLE CLEARANCE
(DOOR OPEN) TOO
SMALL

A. ADJUST OR REPLACE
MECHANISM

B. SHIM THE CLUTCH
CONE ASSEMBLY

5-4

SYMPTOM

I POSSIBLE CAUSE

I CORRECTIVE ACTION

6. FRONT DOOR

A. DOOR LATCHING

A. ADJUST OR REPLACE DOOR

WON’T OPEN

MECHANISM NEEDS

LATCH MECHANISM

ADJUSTMENT OR IS

BROKEN

7. DRIVE/CONSOLE

A. DRIVE MOTOR SPEED

A. ADJUST DRIVE MOTOR

SYSTEM WILL

INCORRECT

SPEED

NOT "BOOT UP"

B. CAN'T FIND TRACK 00

B. ADJUST TRACK 00 STOP

SETSCREW

C. ELECTRICAL MALFUNC-

C. REPLACE AND/OR

TION, SIDE AND/OR

TROUBLESHOOT PCB(S)

REAR PCB(S)

D. STEPPER MOTOR MAL-

D. REPLACE STEPPER MOTOR

FUNCTIONING

•

E. RADIAL TRACK MIS-

E. COMPLETE RADIAL TRACK

ALIGNMENT

ALIGNMENT

F. BAD HEAD

F. REPLACE HEAD ASSEMBLY

8. OCCASIONAL

A. DAMAGED DISKETTE

A. REPLACE DISKETTE

READ ERRORS;

B. DIRTY OR MAGNETIZED

B. CLEAN AND DEMAGNETIZE

ALL TRACKS:

HEAD

HEAD

C. WORN OR DIRTY HEAD

C. REPLACE HEAD PRESSURE

PRESSURE PAD

PAD

5-5

9

INNER TRACKS:

OUTER TRACKS

DRIVE WON'T
WRITE DATA

POSSIBLE CAUSE

D. OVERSTRESSED PRESSURE
PAD ARM SPRING

A. DRIVE MOTOR SPEED
INCORRECT

B. ELECTRICAL MALFUNC-
TION IN READ CIRCUIT

B.

DRIVE MOTOR SPEED
INCORRECT

ELECTRICAL MALFUNC-
TION IN READ CIRCUIT

A. DAMAGED DISKETTE

B. ELECTRICAL MALFUNC-
TION IN WRITE CIRCUIT

D.

A.

B.

A.

B.

A.

B.

CORRECTIVE ACTION

REPLACE SPRING OR
HEAD ASSEMBLY

ADJUST DRIVE MOTOR
SPEED

REPLACE AND/OR
TROUBLESHOOT REAR
PCB, SIDE PC B OR
HEAD. C CHECK FOR SLOW
Q 1 0 2 OR Z 1 04 ON SIDE
PCB . )

ADJUST DRIVE MOTOR
SPEED

REPLACE AND/OR
TROUBLESHOOT REAR
PC B, SIDE PCB OR HEAD.
(CHECK R 1 5 5 VALUE ON
REAR PCB.)

REPLACE DISKETTE
REPLACE AND/OR
TROUBLESHOOT REAR
PCB, SIDE PCB OR HEAD

5-6

SYMPTOM

POSSIBLE CAUSE

CORRECTIVE ACTION

I

10. VARIOUS ERROR
CODES DURING
OPERATION

11. DRIVE

INCOMPATABI LITY

A.

12 .

DRIVE WRITES
ONTO WRITE-PRO-
TECTED DISKETTES

A.

ELECTRICAL OR ME-
CHANICAL MALFUNCTIONS

DRIVE MOTOR SPEED
INCORRECT
RADIAL TRACK MIS-
ALIGNMENT

MALFUNCTIONING WRITE
PROTECT CIRCUIT

A. CHECK TO ENSURE
DISKETTE IS NOT
WRITE-PROTECTED

B. REPLACE Z 1 0 5

C. REPLACE AND/OR
TROUBLESHOOT PCBS,
TRANSPORT

A. ADJUST DRIVE MOTOR
SPEED

B. COMPLETE RADIAL TRACK
ALIGNMENT

A. CHECK WRITE PROTECT
LED/ PHOTO-TRANSISTOR
WIRING HARNESS CON-
NECTIONS. REPLACE
TRANSPORT' LEFT
SI DEPLATE.

5-7

5-8

DISASSEMBLY/REASSEMBLY

6-2

DISASSEMBLY AND REASSEMBLY

The level of Disk Drive disassembly will vary with the
specific problem encountered. Some procedures list steps
which are themselves procedures; ie. " Disassemble the Drive
case . " When you encounter an underlined step, turn to that
procedure first and follow it before proceeding.

SPECIAL NOTES

1. Refer to the Disk Drive and 400/800 Operators Manuals
for proper Drive setup and operation.

2. Disk Drive circuitry includes static sensitive MOS devices.
All Drive repairs should be performed at static protected
work surfaces. Anyone handling Drive PCBs should wear

a grounding strap.

3. To prevent thread damage, use only the specified screws.

4. Overtightening screws will strip the threads on plastic
and aluminum parts. Do not exceed 6 inch pounds torque
for plastic parts, or 10 inch pounds torque for
aluminum parts.

5. Internal wiring connections are made with wiring
harnesses terminated by nonpolarized pins and jacks.

Be sure all pins and jacks are correctly installed
before trying to operate the Disk Drive.

6. When reassembling the Drive, ensure that all wiring
harnesses are routed in such a way as to prevent them
from being pinched between reassembled parts.

6-3

DISASSEMBLY FLOW CHART

Identify the level of disassembly
required and complete the sequence
of steps indicated above.

6-4

1. With the Disk Drive rightside up on a suitable
® ur f ac e, locate and remove the four adhesive !
covers on the tophousing.

2. Locate and remove the four screws securing the
housing to the base.

3. Lift the tophousing from the base, and set it

CAUTION: The record/playback and erase head sub-a

is extremely sensitive to magnetic fields. DO NOT
magnetized tools or articles when working inside tl
Drive case or near the Drive transport.

REMOVING THE COMMON BASEPLATE

NOTE: Removal of either the side PCB, rear PCB or

Drive transport requires removal of their common baseplate
from the Disk Drive base.

1 • Disassemble the Disk Drive case .

2. Disconnect the AC transformer power cord from the
PWR jack at the rear of the Drive chassis.

3. Disconnect any I/O cables from the I/O CONNECTORS
at the rear of the Drive chassis.

4. Locate and remove the five screws securing the common
baseplate to the base.

6-6

5. Carefully lift the baseplate from the base. Note
that each of the bosses in the base is topped with
a rubber washer.

coverplate will lift out at the same time. Remove the
coverplate from the baseplate and set it aside.

6. Place the baseplate on a suitable static protected
work surface.

REMOVING THE SIDE PCB

1- Disassemble the Disk Drive case.

2. Remove the common baseplate from the Drive base.

harness ( nonpolarized - black, green, (blank) ,
red, black) from the side PCB.

4. Locate and disconnect the stepper motor wiring

harness (nonpolarized - black, white, red, green,
brown) from the side PCB.

NOTE: See Appendix for alternate wiring harness arrangement.

6-8

5 .

Locate and remove the three screws securing the
side PCB and its center ground bracket to the common
baseplate.

6. Grasp the side PCB at both its front edge and

its upper rear corner. Lift the PCB straight up
to disengage its rear jack from the row of pins

NOTE: You may have to rock the PCB slightly to overcome

the jack— to— pin tension between the two PCBs.

7. Place the side PCB on a static protected work surface.

6-9

REMOVING THE RF SHIELD (SIDE PCB)

Disassemble the Disk Drive case.

Remove the common baseplate from the Drive base

Remove the side PCB from the common baseplate.
Locate and carefully straighten the three tabs
securing the RF shield case halves together on
the side PCB.

CAUTION: Excessive bending of the metal tabs will

break them. DO NOT bend the tabs anymore than
necessary.

Locate and remove the two screws securing the case
halves to the ground bracket and PCB.

Carefully disengage the case halves from each other
and the PCB. Set the case halves aside.

REMOVING THE DRIVE TRANSPORT

1 ♦ Disassemble the Disk Drive case.

2 * Remove the common baseplate from the Drive base.

3. Remove the side PCB.

4. Grasp the transport securely, tip the assembly
upside down, and place it on a suitable work surface.

5. Locate and remove the four screws that secure the
transport to the baseplate. The screws are accessible
only from the underside of the baseplate.

CAUTION :

alignments necessary for proper Disk Drive operation.

ver Y careful not to jar or damage the transport or
any of its associated sub-assemblies and components.

6. Place the transport and baseplate on a suitable
work surface.

6-11

REMOVING THE REAR PCB

Disassemble the Disk Drive case.

Remove the common baseplate from the Drive base.
Remove the side PCB from the common baseplate.
Locate and remove the four screws securing the rear
PCB to the common baseplate.

5. Grasp the rear PCB on both side edges. Carefully
lift the board straight up far enough to disengage
the board's two right side jacks from the six device

pins .

NOTE: You may have to rock the PCB slightly to

overcome the jack-to-pin tension between the PCB and
the pins attached to the common baseplate.

6. Lift the rear PCB away from the baseplate and
place it on a suitable work surface.

6-12

REMOVING Q113 (TRANSISTOR) /A108 (VOLTAGE REGULATOR)

1* Disassemble the Disk Drive case.

2.

Remove

the

common

baseplate

from the Drive base.

3.

Remove

the

side

PCB from the

common

baseplate.

4.

Remove

the

rear

PCB from the

common

baseplate.

5.

Locate

and

remove

the single

screw

securing the

device (either transistor Q113 or voltage regulator
A108) to the common baseplate.

NOTE: If you are removing Q113 you should find an

insulating plate between the back of the device and the
common baseplate. Also, both Q113 and A108 use the
common baseplate as a heatsink. Each device and Q113's

insulating plate should be coated with heat transfer com'
pound.

6. Lift the device (Q113 or A108) from the baseplate
and set aside.

6-13

REMOVING THE TRANSPORT DRIVE BELT

1 • Disassemble the Disk Drive case.

2. Remove the common baseplate from the Drive base.

3 • Remove the Drive transport from the common baseplate,

4. Carefully lay the transport on its side.

5. Locate and remove the drive belt.

NOTE: To remove the drive belt without stretching or

damaging it, rotate the large flywheel (marked for
strobe) while easing the belt off the outside edge of
the flywheel.

6-14

REMOVING THE TRANSPORT DRIVE MOTOR

1 • Disassemble the Disk Drive case.

2 . Remove the common baseplate from the Drive base.

3 • Remove the Drive transport from the common baseplate.

4. Remove the drive belt from the transport.

5. Locate and disconnect the single black ground lead
coming from the drive motor wiring harness and going
to the transport casting.

6. While supporting the drive motor with one hand, locate
and remove the two screws securing the drive motor

to the transport casting.

7. Separate the drive motor from the casting.

6-15

REMOVING THE CARRIER ASSEMBLY

1 • Disassemble the Disk Drive case.

2 • Remove the common baseplate from the Drive base.

3 * Remove the Drive transport from the common baseplate.

4. Locate the head assembly and slide the assembly
all the way to the rear of its travel.

5. Locate and loosen, approximately two full turns, but
do not remove, the two screws securing the carrier
assembly to the rear of the transport casting.

6. Locate the four screws securing the front panel bezel

to the side guide assemblies and the transport casting.

7. Loosen (do not remove) the two bottom screws
approximately four full turns.

8. Remove the two top screws.

6-16

9. Push the door release button at the front of the
transport to disengage the carrier assembly from
the door latch. Lift the assembly far enough to
clear the latch mechanism and release the button.
Lower the door to a resting position.

10. Now completely remove the two screws at the rear
of the transport casting.

11. Pull the top of the front panel bezel forward.

12. Carefully, lift the carrier assembly out of the transport.

CAUTION: You will have to tilt the carrier assembly slightly

to clear the head assembly's pressure pad arm. DO NOT
lift the pressure pad arm higher than it would be lifted
by the door arm during normal Drive operation. Lifting
the pad arm too far will distort its pressure spring,
changing the pressure pad's loading effect on the head.

6-17

REMOVING THE TRANSPORT FLYWHEEL/DRIVE SPINDLE

1 • Disassemble the Disk Drive case.

2. Remove the common baseplate from the Drive base.

3 • Remove the Drive transport from the common baseplate.
4 . Remove the drive belt from the transport.

3 • Remove the carrier assembly from the transport.

6. Carefully lay the transport on its side.

Screw

7. Locate the single screw in the center of the
flywheel. Holding the flywheel with one hand,
remove the screw.

NOTE: See the following illustration of the

flywheel/casting/spindle relationship. The specific
number and placement of the washers is very important
and helps to determine diskette speed during operation.

DO NOT lose any of the washers you remove during this step.

6-18

*

Diskette

Drive

Spindle

I

8. Being very careful not to lose any washers, hold
the drive spindle with one hand and carefully pull

the flywheel away from the casting with the other hand.

9. Pull the spindle from the casting.

6-19

REMOVING THE TRANSPORT SPINDLE SHAFT BEARINGS

1 .

Disassemble the Disk Drive case.

2.

Remove

the

common baseplate from the Drive

base.

3.

Remove

the

Drive transport from the common

baseplate.

4.

Remove

the

drive belt from the transoort.

£. *

5.

Remove

the

carrier assembly from the hranqnnrf

6.

Remove

the

—

flywheel and drive spindle from

the

transport.

7.

Diskette

Drive

Spindle

Upper

Spindle Shaft
Bearing

Casting

Bore

Lower

Spindle Shaft
Bearing

The top spindle shaft bearing may have lifted
from the casting when you removed the drive spindle.
If it did not, very carefully pry the bearing out
of the casting.

8. Very carefully push the bottom bearing out of

the casting (push from the top side of the casting,
being very careful not to damage the casting bore) .

6-20

REMOVING THE HEAD ASSEMBLY

1.

Disassemble the Disk Drive

case.

2.

Remove

the

common baseplate

from

the

Drive

base .

3.

Remove

the

Drive transport

from

the

common

baseplate .

4.

Remove

the

carrier assembly

from

the

transport.

Nylon

Clamp

5. Locate the nylon clamp securing the record/playback
and erase head I/O wiring harness to the right rear
corner of the casting. Release the clamp from the
casting.

6. Push the head assembly as far to the rear of the
Drive as it will slide.

7. Locate and remove the ground lead (black wire from
the drive motor wiring harness) faston from the rear
of the casting.

6-21

8. Locate the two screws securing the stepper motor

positioning band to the right side of the head
assembly.

a. Remove the rear screw, being very careful not

to crimp or damage the band, and noting the screw
and washer arrangement.

b. Slide the head assembly carriage forward
enough to allow you to remove the front band
screw. Remove the front screw, again noting
the screw and washer arrangement.

NOTE: The stepper motor positioning band is very

delicate and very important to the operation of the Drive.
DO NOT kink or damage the band in any way.

6-22

REMOVING THE STEPPER MOTOR

1 .

Disassemble the Disk Drive case.

2.

Remove the common baseplate from the Drive

case.

3.

Remove the Drive transport from the common

baseplate.

4. Locate the two screws securing the stepper motor

positioning band to the right side of the head assembly.

a. Remove the rear screw, being very careful not to
crimp or damage the band, and noting the screw and
washer arrangement.

b. Slide the head assembly carriage forward enough
to allow you to remove the front band screw.

Remove the front screw, again noting the screw
and washer arrangement.

NOTE: The stepper motor positioning band is very delicate

and very important to the operation of the Drive. DO NOT
kink or damage the band in any way.

6-24

5 .

Locate the alien-head setscrew securing the head position-
ing strap pulley to the stepper motor drive shaft
(topside of casting) .

6. Back the setscrew out about 1 turn (counterclockwise).

7. Remove the band/pulley from the stepper motor shaft
and set it aside.

8. Locate the two nuts securing the stepper motor to
the casting.

9. Lay the casting on its left side.

10. While supporting the stepper motor with your right
hand, remove the two securing nuts.

11. Carefully separate the motor from the chassis, while

P u H^- n 9 the motor wiring harness out of its chassis
slot.

6-25

REASSEMBLY

RF SHIELD
( SIDE PCB )

6-26

INSTALLING THE STEPPER MOTOR

1. Install a split rubber grommet on the
stepper motor wiring harness.

2. Lay the transport on its left side.

3 . Position the stepper motor to the underside
of the transport casting. The motor's
wiring harness should lie toward the rear
center of the casting.

CAUTION: The head is subject to magnetization

from external fields. DO NOT use magnetized tools
or allow the head to get near any equipment producing
strong magnetic fields.

6-27

4 . Install a flatwasher, a splitring lockwasher,
and a 1/4" hexnut onto each of the two
stepper motor stud bolts projecting through
top of the casting. Lightly tighten
the nuts.

5 . Carefully install the head positioning
band pulley onto the stepper motor drive
shaft (projecting through the top of the
casting) . if the pulley does not easily
slip onto the motor shaft, back the pulley's alien-
head setscrew a little farther out
of the pulley. DO NOT tighten the setscrew
at this time.

NOTE: The stepper motor positioning band is

delicate and very important to the operation
of the Drive. DO NOT kink or damage the band in
any way.

6-28

6 .

7 .

8 .

9 .

10 .

11 .

Special

Bracket Washer

Carefully position the head assembly so that
you can connect the positioning band to
the assembly's right rear corner.

Install, but do not tighten, the rear screw,
splitring lockwasher, and special bracket
washer to hold the rear section of the
positioning band to the head assembly.
Carefully pull the front section of the
positioning band forward until its screw hole
is located over the matching screw hole on
the front corner of the head assembly.
Install, but do not tighten, the screw,
splitring lockwasher, and flatwasher to
secure the band to the head assembly.

Gently slide the head assembly back and forth
on its guiderods. This will center the band
pulley on the stepper motor shaft.

Tighten the rear band retaining screw.

CAUTION: DO NOT exceed 6 inch lbs. torque when

tightening screws into plastic parts.

12 . Use a pointed tool (ie. X-acto knife point,
etc.) to hook the small hole on the front
end of the positioning band. Pull forward
slightly on the band while tightening the
front band retaining screw.

13. Slide the wiring harness' grommet up into the
slot at the rear of the transport casting.

14 . Attac h the transport to the common baseplate.

1^* the common baseplate to the Drive base.

6-30

INSTALLING THE HEAD ASSEMBLY

CAUTIONS: The head is subject to magnetization

from external fields. DO NOT use magnetized
tools or allow the head to get near any equip-
ment producing strong magnetic fields.

The head is also damaged by dirt and oils.

DO NOT touch either the head or the pressure pad
with your fingers.

DO NOT lift the pressure pad arm farther from the
head carriage than the arm would be lifted during
normal Disk Drive operations. Lifting the arm
too far will distort its pressure spring,
changing the arm's loading effect on the head
during operation.

The stepper motor positioning band is
delicate and very important to the operation of
the Drive . DO NOT kink or damage the band in
any way.

6-31

the head assembly carriage.

Carefully lower the carriage/guiderods
assembly into position in the transport
casting. Ensure that the head wiring harness
lies down in the underside of the transport.
Wrap a small piece of masking tape around \
the head assembly's wiring harness, about
3" from the head. Install the nylon cable Vs>
clamp over the tape and snap the clamp into
the hole provided at the back of the casting.
Feed the wiring harness up through the
rectangular hole at the right rear corner
of the transport casting.

6-32

Csnter (f ront— to—back) the two head assembly
^uiderods in their transport casting slots.

Position the two guiderod clamps onto the
casting, over the ends of the guiderods.

Install, but do not tighten, the front clamp
screw including a splitring lockwasher.

Install, but do not tighten, the rear clamp
screw including two male faston terminals
and a splitring lockwasher.

Tighten the two clamp screws to 10 inch lbs. torque

Pulley
Setscrew

10. Carefully position the head assembly so that
you can connect the positioning band to the
assembly's right rear corner.

11. Install, but do not tighten, the rear screw,
splitring lockwasher, and special bracket
washer to hold the rear section of the
positioning band to the head assembly.

12- Carefully pull the front section of the

positioning band forward until its screw hole
is located over the matching screw hole on
the front corner of the head assembly.

13* Install, but do not tighten, the screw,
splitring lockwasher, and flatwasher to
secure the band to the head assembly.

14- Locate the alien-head setscrew securing

the positioning band pulley to the stepper
inotor driveshaft. Back the setscrew out
(counterclockwise) about 1/4 turn.

15. Gently slide the head assembly back and forth
on its guiderods. This will center the

band pulley on the stepper motor shaft.

16. Tighten the rear band retaining screw.

CAUTION: DO NOT exceed 6 inch lbs. torque when

tightening screws into plastic parts.

18.

19.

Use a pointed tool (ie. X-acto knife point,
etc.) to hook the small hole on the front
end of the positioning band. Pull forward
slightly on the band while tightening the
front band retaining screw.

Attach the black ground lead (drive motor
wiping harness) to one of the faston lugs
at the rear of the transport.

6-35

INSTALLING THE TRANSPORT SPINDLE SHAFT BEARINGS

1. Gently insert either the top or bottom (or both)
shoulder bearings into the casting bore.

There should be a slight friction fit.

NOTE: If excessive force is required, you

probably have incorrectly identified the bearing.

Obtain the correct bearing before proceeding.

. Upper Spindle Sh
Shoulder Bearing

Transport
Casting Bore

Lower Spindle S
Shoulder Bearin

2. Ensure that the shoulder of the bearing is
firmly seated flat against the casting.

3 . Attach the flywheel and drive spindle to
the transport.

6-36

INSTALLING THE TRANSPORT FLYWHEEL/DRIVE SPINDLE

1* Lay the transport casting on its side.

2. From the top side of the casting, insert-
the diskette drive spindle into the shoulder
bearings .

3. Assemble the necessary combination of
washers along with the flywheel and screw.

See the illustration for the flywheel/casting/spindle
relationship.

The specific number and placement of the
washers is very important and helps to
determine diskette speed during operation.

6-37

Screw ^

From the bottom side of the casting, position
the flywheel, screw and washer combination
over the bottom of the spindle shaft. Screw
the assembly together. Torque the screw to
6 inch lbs . .

Rotate the flywheel and check for wobble,
runout or binding of either the flywheel or
drive spindle. Adjust the assembly as
necessary.

Attach the carrier assembly to the transport.

6-38

INSTALLING THE CARRIER ASSEMBLY

CAUTIONS: This procedure requires that you lift

the head assembly pressure pad arm in order
to position its lift arm onto the carrier
assembly. DO NOT lift the pressure pad higher
than it would be lifted by the carrier assembly
during normal operations. Lifting the pad arm
too far will distort its pressure spring,
changing the pad's loading effect on the head.

The head is subject to magnetization from
external fields. DO NOT use magnetized tools
or allow the head to get near any equipment
producing strong magnetic fields.

1 . Ensure that the transport front panel bezel
is tilted forward from both guide assemblies
for extra clearance at the top.

6-39

2 • Carefully lower the carrier assembly into
position over the transport casting. Lift
the head assembly's pressure pad arm just
enough to position it onto its carrier
assembly slide area.

3 • Install and slightly tighten the two screws,
splitring lockwashers, and flatwashers at
the rear corners of the carrier assembly.

6-40

4 . Push the bezel back to its normal position
and install the two top screws.

5 . Tighten the four screws securing the bezel
to the transport.

6 . Latch the carrier assembly closed (down)
at the bezel.

7 . Horizontally center the door in the door
opening of the bezel.

8. Tighten (10 inch lbs.) the two screws secur-
ing the rear corners of the carrier assembly
to the rear of the transport casting.

9 . Press the front door release button. Ensure
that the door opens and the carrier assembly
lifts the head assembly pressure pad arm.

6-41

10. With the door open, observe the gap between the
top edge of the diskette drive spindle and the
bottom edge of the clutch cone assembly. Be sure
a diskette can move in and out without being
scratched or pinched.

NOTE: The spindle/cone clearance is critical

to ensure that the diskette is ejected when
opening the front door. Too little clearance
may cause the back edge of the cone to catch the
edge of the diskette hub hole, preventing the
diskette from being ejected. Test the ejection
process using a standard diskette.

■Retaining Clip

11. To adjust the clearance, compress the clutch cone
into the doorarm, forcing the clutch cone shaft up
out of the top of the carrier assembly.

12 . Locate and remove the retaining clip from
the shaft.

13. Place another flatwasher over the shaft and
replace the retaining clip.

14. Release the clutch cone and return to step 10.

6-42

BLOCK

LATCH

BLOCK

15. With the carrier assembly open, push the
diskette eject block (right rear corner)
until it latches into its rear position under
the latch lever.

16 . Close the carrier assembly and then press the
release button to reopen the door.

17. Check to see that the diskette eject block
freely returned to its forward position when
the carrier assembly opened.

18. If the block did not return, bend either the
latching lever or the lever lifting arm to
adjust the mechanism.

19. Repeat steps 15 thru 18 until the diskette
eject mechanism works as indicated.

20. If necessary, install the drive belt .

21* Attach the transport to the common baseplate.

6-43

INSTALLING THE DRIVE MOTOR

1* La Y the Drive transport on its side.

2. Position the drive motor onto the top side
of the casting. The motor's wiring harness
should exit the motor toward the center
rear of the transport.

3. While supporting the motor with one hand,
install the two screws, splitring lockwashers,
and flatwashers to secure the motor to the
transport.

4. Torque the two screws to 10 inch lbs.

5 * Attach the drive belt to the transport.

6-44

INSTALLING THE TRANSPORT DRIVE BELT

1. Lay the transport on its side.

2. Loop the drive belt over the drive motor
drive hub. Carefully ease the belt onto the
flywheel while rotating the flywheel.

NOTE: DO NOT stretch or damage the drive belt.

It is primarily responsible for diskette speed
and any variations in diskette speed caused by
a stretched or damaged drive belt can cause
errors during read and write operations.

3. Refer to the adjustments section of this manual
and complete the drive belt adjustment.

4 • Attach the transport to the common baseplate.

6-45

INSTALLING Q113 (TRANSISTOR) /A108 (VOLTAGE REGULATOR)

2. If you are installing Q113 (transistor ) :

a. Apply heat transfer compound to both
sides of the mica insulating plate.

b. Place the insulating plate into location
on the common baseplate.

c. Place the transistor into position on
top of the insulating plate.

d. Secure the transistor/insulating plate
combination to the common baseplate with
a #4-40 x 3/8" PHIL HD. screw, shoulder
washer, #4 splitring lockwasher, and a #4
STD hexnut.

6-46

Screw

3. If you are installing A108 (voltage regulator)

a. Apply heat transfer compound to the back
of the voltage regulator.

b. Position the regulator onto the common
baseplate.

c. Secure the device to the baseplate with
a #4 x 1/4 THD F PHIL HD. screw.

4 - Attach the rear PCB to the common baseplate.

6-47

INSTALLING THE REAR PCB

1. Carefully lower the rear PCB into position
on the common baseplate. Ensure that the
six device legs at the right side of the
baseplate are correctly seated into the two
three-pin sockets on the PCB.

2. Install and tighten the four screws (#6-32 x
1/4" PHIL HD.) and lockwashers ( #6 splitring)
to secure the PCB to the baseplate.

Connect the transport to the common baseplate.

6-48

INSTALLING THE DRIVE TRANSPORT

CAUTION: The transport provides critical mechanical

alignments necessary for proper Disk Drive
operation. Be very careful not to jar or damage
the transport or any of its associated sub-
assemblies and components.

1. Carefully set the transport upside down on
a suitable work surface.

2. Gently set the transport (upside down) on top

1/4" PHIL HD.) and lockwashers ( #6 splitring)
to secure the transport to the baseplate.

4. Set the assembly rightside up on the work surface.

6-49

5. Locate and connect the < record/playback and
erase head I/O wiring harness (shielded-

red, (blank), blue and either white, black or black,
white) to the rear PCB (nonpolarized, #4).

6. Locate and connect the drive motor/ground
wiring harness (yellow, green, blue, red,
black) to the rear PCB (nonpolarized, #3).*

7. If you removed the side PCB, follow the
procedures to attach the PCB to the common
baseplate,

8. If you did not remove the side PCB during
disassembly:

a. Locate and connect the stepper motor
wiring harness (black, white, red, green,
brown) to the side PCB (nonpolarized, #2) .

b. Locate and connect the write protect
wiring harness (black, green, (blank) ,
red, black) to the side PCB (nonpolarized,

# 1 ) .

9. Go on to step 10.

10 • Attach the common baseplate to the Drive base ,

*NOTE: See Appendix for alternate wiring harness arrangement.

6-50

INSTALLING THE RF SHIELD (SIDE PCB)

CAUTION: Excessive handling of the locating

tabs on the shield case will break them. DO NOT
bend the tabs anymore than absolutely necessary.

Carefully position the case halves onto the
side PCB.

Position the ground bracket onto the side PCB
Install and tighten the two screws (#6-32 x
5/16" THD F, PHIL HD.) to secure the ground
bracket to the PCB and case halves.

Locate and bend the three tabs securing the
RF shield case halves together.

Connect the side PCB to the common baseplate.

INSTALLING THE SIDE PCB

1. Position the side PCB on the common baseplate
(with rear PCB installed) .

BROWN
(STEPPER
BLACK MOTOR)

i if ^

^ li

' RED
(WRITE PROTECT)

m

Gently seat the multipin socket at the rear
lower edge of the side PCB down onto the
pins protruding from the rear PCB.

Install and tighten the three screws (#6-32 x
5/16" THD F, PHIL HD.) that secure the side PCB
and its ground bracket to the common base-

4 .

Locate and connect the stepper motor wiring harness
(black, white, red, green, brown) from the Drive
transport to the side PCB (nonpolarized, #2) .

5. Locate and connect the write protect wiring harness
(black, green, (blank) , red, black) to the side
PCB (nonpolarized, #1) .

6 • Attach the common baseplate to the Drive base.

DRIVE

MOTOR

WRITE

PROTECT

HEAD

I/O

STEPPER

MOTOR

•aoQio

JI03

REAR BO.

•00000

JIOI

SIDE BD.

•01000

JI09

REAR BO.

> Q0 ODD

2696

2696

2696

(6R.) BLACK — »

(+) RED-*
(—) BLUE -»

J

W BLACK

PHOTO -XSTH ,

l+JRED^

• YELLOW
, t GREEN , -

TACH. GEN.
OUTPUT (A.C.)

r

j

BLACK (-), RED— J
L.E.O. (ERAXHEAD)

l -green(+)

J

BLACK

(COMMON) .

WHITE -J

_ { PHASE I )

(pES}<8£»

t

JI02
SIDE BO.

2696

RED

(PHASE 2)

BROWN

, (PHASE 4)

•-GREEN

( PHASE 3)

NOTE: You may also have this wiring harness arrangement.

6-53

INSTALLING • THE COMMON BASEPLATE

]\#>

Ensure that every boss in the base (even
those not used to secure the baseplate) is
topped with a rubber isolation washer.

Position the front coverplate onto the
baseplate/ transport/PCB assembly.

Carefully lower the baseplate into position
in the Drive base, ensuring that the coverplate
is also correctly positioned in the base.

4. Install and tighten the five screws (6 - 1/2"

BT. PHIL HD.) securing the common baseplate
to the Drive base.

5. Refer to the' adjustments section of this manual
and complete the head cleaning and demagnetization
procedure .

6. Refer to the adjustments section of this
manual and complete the radial track align-
ment, speed control adjustment, and track
00 end stop adjustment.

7 • Reassemble the Drive case.

6-55

ASSEMBLING THE DRIVE CASE

1. Carefully position the tophousing onto
the base and coverplate.

Install and tighten the four screws (#6 - 3/4"
SHT MTL PHIL HD.) securing the tophousing to
the coverplate. Install the screw hole covers.
Refer to the final checkout section of this
manual and complete the full checkout procedure
for the Drive.

ADJUSTMENTS

READ/WRITE & ERASE HEAD CLEANING & DEMAGNETIZATION

Both the head and the pressure pad will accumulate

dirt and oxide particles during use. Periodic

cleaning and inspection is necessary for proper Disk Drive

operation.

CAUTIONS: The head is subject to magnetization

from external fields. DO NOT use magnetized tools
or allow the head to get near any equipment producing
strong magnetic fields.

DO NOT lift the pressure pad arm farther from the
head carriage than the arm would be lifted during
normal Disk Drive operations (ie. front door open) .

1. Use a small mirror to inspect the pressure pad
for excessive buildup of oxides and dirt, or
for excessive wear. Replace the head if it is
worn or damaged.

2. Otherwise, clean the head.

NOTE: Use either a cotton swab (preferred) or

a lint-free cloth (ie. chamois) moistened with
either methyl or high quality 91% isopropyl alcohol.
Wipe the head carefully to remove all accumulated
oxide and dirt. Dry the head.

CAUTION: DO NOT use carbon tetrachloride as a

cleaning solution for the head.

7-3

3. To demagnetize the head, hold the energized

demagnetizing tool about 6 inches above the head.
Slowly lower the tool toward the head in a
spiraling motion. DO NOT allow the tool to come
into contact with the head.

DEMAGNITIZER

4. Reverse the procedure as you lift the tool away
from the head. DO NOT turn the tool off until
it is at least 6 inches away from the head.

7-4

RADIAL TRACK ALIGNMENT & SPEED ADJUSTMENT

Radial track alignment and speed adjustment is
necessary to provide optimum diskette compatability
between Drives.

The following are required to perform this
procedure :

A. Oscilloscope, dual trace with A+B function,
and B invert function, with two probes.

B. Atari 400/800 Computer Console with minimum
16 K RADI installed.

C. I/O cables and Console/Drive power packs.

D. Disk Alignment Cartridge or Program.

E. Master Alignment Diskette.

F. 0.050 hex setscrew driver.

G. Non-conductive common blade tuning wand.

The Disk Drive PWR ON lite should be ON and the
BUSY lite should be OFF whenever you are inserting
or removing a diskette from the unit. DO NOT open
the Drive door or turn Drive power off when the
BUSY lite is on.

CAUTIONS: Take extreme care when handling and

storing the master alignment diskette.

7-5

1. Connect the Drive to the Computer Console.

2. Turn the Drive on and wait for the BUSY lite
to go off. Insert the master alignment
diskette.

3. Either insert the disk alignment cartridge
or load the disk alignment program into the
Console .

4. Via the Console, command the Drive to read
track 16.

5. Set the oscilloscope controls as follows:

DISPLAY: A + B, B inverted
TIME/DIV: 20 msec./DIV
VOLTS/DIV: 20 mv/DIV

6. Compensate your scope probes.

7. Connect a ground probe from the scope to the
fas ton lug ground at the rear of the transport.

8. Attach the channel A probe to the rear lead of
CR154 .

9. Attach the channel B probe to the rear lead
of C155 .

7-6

CENTER

LINE

A - AMPLITUDE

FIG A

CAT'S -EYE PATTERN

10. The 'scope should be displaying a repeating
cat's-eye lobe pattern as shown above.
a * the lobes are of equal amplitude, go

on to step 11.

If the lobes are of unequal amplitudes,
proceed as follows:

1. Locate the setscrew securing the stepper
motor positioning band pulley to the
stepper motor shaft.

2. With the Drive still reading track 16,
back the setscrew out (counterclock-
wise) of the pulley about 1/4 turn.

Leave the setscrew driver in the pulley.

3. Slightly rotate the pulley either
clockwise or counterclockwise until
the ' scope shows equal amplitude
cat ' s-eye lobes .

£• Tighten the setscrew and remove the
setscrew driver.

5. Verify that the lobes are still within
80% amplitude of each other. If they
are not, return to step 2.

7-7

§.• Via the Console, command the Drive to

step back to track 00 and return to read
track 16.

TO

TRACK 17

ON

TRACK 16

- TO
TRACK 15

+1 mil off
track 16

+2 mil off
track 16

+3 mil off
track 16

-1 mil off
track 16

-2 mil off
track 16

-3 mil off
track 16

"Cat's Eyes" DISPLAY AS A FUNCTION OF

READ HEAD to TRACK 16 POSITION

7. Verify that the lobes are still within 80%
amplitude of each other. If they are not,
return to step 2 .

ii* Via the Console, command the Drive to
step out to track 32 and return to read
track 16.

7-8

2 .* Verify that the lobes are still within
80% amplitude of each other. If they
are not, return to step 2 .

NOTE: Steps 6^ thru 9^ check the hysterisus within

the head positioning system. If you are unable to
achieve the results indicated, suspect: 1) a broken
damaged setscrew; 2) a binding and misaligned
positioning band; 3) binding of head assembly to
guiderods; or 4) a bad stepper motor.

11* Disconnect the ' scope probes (except for the
ground lead) from the drive circuit.

12. Reset the 'scope DISPLAY to channel A only.

13. Attach the A channel probe to ANODE side of
CR110 (tachometer output) .

7-9

14. Command the Drive to read any track.

15. Refer to the following guide for correct
tachometer frequencies. If the tested fre-
quency is not correct, adjust R142.

SPEED ADJUSTMENT GUIDE

DRIVE

BELT

DRIVE MOTOR
PULLEY DIAM.

TACH

FREQ.

1 CYCLE
= APPROX

DRIVE MTR.
PART NUMBER

Mylar

(yellow)

.250"

390 Hz

2.564 msec

3-35003-002

Mylar

(yellow)

.300"

320 Hz

3.125 msec

3-35003-001

Neoprene

(black)

.300"

305 Hz

3.279 msec

3-35003-001

TRACK 00 STOP ADJUSTMENT

The following are required to perforin this procedure:

A.

B.

C.

D.

E.

F.

Atari 400/800 Computer Console with minimum
16K RAM installed.

I/O cables and Console/Drive power packs.
Disk Alignment Cartridge (Console) or Disk
Alignment Program.

Master Alignment Diskette.

0.050 hex setscrew driver.

0.010 inch flat or round feeler gage.

1. Connect the Drive to the Computer Console.

2. Turn the Drive on and wait for the BUSY lite
to go off. Insert the master alignment
diskette.

Either insert the disk alignment cartridge
or load the disk alignment program into the
Console.

4. Via the Console, command the Drive to read
track 00.

7-11

5. Locate the track 00 stop setscrew at the rear
of the Drive transport.

clearance between the setscrew and the rear
corner of the head carriage plastic molding.

7. Command the Drive to step out to any track
above 30, and then return to track 00.

8. Verify that upon returning to and reading track
00, the carriage does not butt against the
setscrew.

7-12

DRIVE BELT ADJUSTMENT

Drive belt adjustments are completed with NO power
applied to the unit.

The transport will have either the older (yellow)
mylar drive belt or the newer (black) neoprene
drive belt. Proper adjustment of the mylar belt
requires the use of a tensiometer or suitable
substitute capable of measuring 17+1 grams.

MYLAR (YELLOW) DRIVE BELT

1. Loosen but do not remove the- two screws
securing the drive motor to the transport
casting.

7-13

17±1 grams
(either leg)

2. Adjust the drive motor position so that the
tension on either leg of the drive belt reads
17+1 grams on the tensiometer (or equivalent
measuring device) .

3. Tighten the two drive motor screws.

4. Verify the belt tension of 17+1 grams,
returning to step l'if necessary.

NEOPRENE (BLACK) DRIVE BELT

1. Loosen but do not remove the two screws
securing the drive motor to the transport
casting.

2. Postition and hold the drive motor as near
to the drive spindle/flywheel as possible.

3. Tighten the two drive motor screws.

7-14

PARTS LISTS

8-1

8-2

QTY . REQUI

ITEM

NO.

PART

NUMBER

DESCRIPTION

PER

01

1

C014757

PRODUCT CARTON

1

2

C014758-02

END CAP

1

3

C014758-01

END CAP

1

4

C015200

DOS/FILE MGR.

1

5

C014763

INSERT

1

6

CA014748

POWER ADAPTER (PKG'D)

1

7

CA014862-01

DISK PROGRAM CX8101

1

8

C014760

INSTRUCTION MANUAL

1

9

C015554

DOOR CLOSE WARNING SHEET

1

10

C016065

INSERT SHEET

1

11

C014759

POLY BAG

1

12

CA014156

FINAL ASSY.

1

13

CAO 14 15 7

UPPER ASSY.

1

14

C014105

PANEL LABEL COVER .

1

15

C012972

COMMON BASE

1

16

C014106

HOLE COVER LABEL

4

17

88-1010

MOUNTING PAD

5

18

CAO 14 15 8

LOWER ASSY.

1

19

CA014318

FASTENER-BASE ASSY.

1

20

C014324

FASTENER

4

21

C012972

COMMON BASE

1

22

23

C014086

CONNECTOR LABEL

1

24

25

88-1004

RUBBER FEET

4

26

C014085

SERIALIZATION LABEL

1

27

28

CAO 14 15 9

PANEL ASSY.

1

29

C014039

LOGO LABEL

1

30

C014082

NAMEPLATE LABEL

1

SOURCE: CA014139-XX
lof 2 REV 10

8-3

QTY . REQU

ITEM

NO.

PART

NUMBER

DESCRIPTION

PER VERS I
01

31

C012976

DISC PANEL, PRIMARY

1

32

C014026

ALTERNATE FOR ITEM 31

_

33

CA014160

MOUNTING PLATE ASSY.

1

34

75-046

LOCKWASHER

8

35

CA014072

DISK DRIVE

1

36

72-1604S

SCREW #6-32X1/4 PHIL. HD.

4

37

72-1406S

SCREW #4-40X3/8 PHIL. HD.

1

38

72-CL404

SCREW #4X1/4 THD.FRM.PHIL.HD.

1

39

C014814

WASHER, SHOULDER

1

40

C014811

INSULATOR

1

41

75-044

LOCKWASHER

1

42

75-914C

NUT #4

1

43

CA014833

PCB ASSY. (REAR)

1

44

CA014161

PCB SUB-ASSY. (REAR)

1

45

C014025

PCB FAB

1

46

72-CL605

SCREW #6X5/16 THD . F .PHIL. HD.

3

47

72-1604S

SCREW #32X1/4 PHIL. HD.

4

48

CA014834

PCB ASSY. (SIDE)

1

49

CA014162

PCB SUB-ASSY. (SIDE)

1

50

C014024

PCB FAB

1

51

72-CL605

SCREW

2

52

53

54

55

C014138

GROUND BRACKET

1

56

C014136

RF SHIELD (INSIDE/COMPONENT)

1

57

C014137

RF SHIELD (OUTSIDE/TRACE)

1

58

59

C012977

MOUNTING PLATE

1

SOURCE: CA014139-XX
lof 2 REV 10

8-4

ITEM

NO.

PART

NUMBER

60

61

62

63

75-AL612

64

82-AL608

65

66

67

68

69

CA014122

70

CA014121

71

72

73

C011506

74

75

C014845

76

77

CA015303

78

C015304

79

C015305

80

81

82

C015936

83

CA015598-XX

DESCRIPTION

QTY. REQU
PER VERS I
01

SCREW #6-3/4 SHEETM . P . H . PHIL . 4

SCREW #6-1/2 B.T.PHIL.HD. 5

CABLE ASSY. (13 PIN) 1

CABLE SyB-ASSY. 1

SHIPPING LABEL 1

WARRANTY CARD 1

POLY ENVELOPE ASSY. 1

RETAILER WARRANTY CARD 1

POLY ENVELOPE 1

PUBLICATIONS QUESTIONNAIRE 1

SERVICE CENTER LIST PACKET 1

SOURCE: CA'01 4 13.9 -XX
2of 2 REV 10

8-5

ITEM

NO.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20
21
22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

PART NUMBER

QTY

DESCRIPTION

C014179-03

C014179-04

C014179-02

C014179-07

C014180-03

CO 14 180- 10
C014180-07
C014 181-01.

CO 14 181-6 3

C014369

1

CAP

, CER,

AXIAL:

lOpf, 20%, COG, C122

1

It

ft

If

33pf , 5%, COG, C141

4

ft

tl

tt

47pf, 10%, COG, C101,103,131, 119

1

ft

ft

tt

62pf, 10%, COG, C105

4

ff

ft

tt

lOOpf, 20%, X7R, C110 ,130, 139, 140

1

It

tl

ft

390pf, 5%, X7R, Clll

1

ft

tt

II

470pf , 20%, X7R, C106

16

It

tt

ft

•OOluf, +80-20%, Z5U, C113, 116-118,
C123-129, 134-138

8

tt

ft

tt

• luf, +80-20%, Z5U, C102 , 104 , 107-109
C114 ,115 ,133

1

It

ELECTROLYTIC,

RADIAL: 4. 7uf , 35V, +75-10%, C132

14-51R1

14-5151

14-5221

14-5271

14-5331

14-5471

14-5102

14-5152

1

1

1

2

1

1

6

1

RESISTOR: 1.1 ohm, 1/4W, 5%, R125
" 150 ohm, 1/4W, 5%, R117

" 220 ohm, 1/4W, 5%, R103 ,

" 270 ohm, 1/4W, 5%, R120,126

" 330 ohm, 1/4W, 5%, R132

470 ohm, 1/4W, 5%, R106
" IK, 1/4W, 5%, R118, 121-124, 129

" 1.5K, 1/4W, 5%, R114

14-5332 1
14-5472 4
14-5562 2
14-5103 4
14-5153 2
14-5273 1
14-5333 1
14-5393 1
14-5473 2
14-5104 2
14-5224 1
14-5750 1

3.3K, 1/4W, 5%, R115

4.7K, 1/4W, 5%, R110,116,128,133

5.6K, 1/4W, 5%, R101,102

10K, 1/4W, 5%, R105, 109, 113,134

15K, 1/4W, 5%, R112,108

27K, 1/4W, 5%, R131

33K, 1/4W, 5%, Rill

39K, 1/4W, 5%, R10 4

47K, 1/4W, 5%, R119 , 130

100K 1/4W, 5%, R135, 136

220K 1/4W, 5%, R127
75 ohm, 1/4W, 5%, R175

C014702

C014384

31-1N914

1 INDUCTOR: 4 70uh, L101

2 ” FERRITE BEAD, L102>103

3 DIODE: 1N914, CR120,CR121, CR122

810 SIDE BOARD

SOURCE: CA014162

lof 4 REV 10

8-6

ITEM

NO.

PART NUMBER QTY .

DESCRIPTION

38

31-1N4001

5

DIODE: 1N4001, CR10 1-104 ,106

39

40

C014808 -01

1

DIODE, ZENER: 1N523TB, 5.1V, +5%, CR107

41

C014394

4

TRANSISTOR: Q106-109

42

33-2N3906

3

2N3906, Q 101 ,103 ,104

43

34-2N3904

4

" 2N3904 , Q10 2, 105,110,111

44

CO 14 31 6

1

CRYSTAL" 1.000000 mhz, X101

45

C014386-07

2

SOCKET, IC: 24 PIN

46

C014386-08

1

SOCKET, IC: 28 PIN

47

C014386-09

2

SOCKET, IC: 40 PIN

48

C014386-02

6

SOCKET, IC: 14 PIN

49

C014717-01

1

CONNECTOR: 23 PIN, P101

50

C014719-02

2

CONNECTOR: 5 PIN, J101,102

51

52

C014397-XX

1

SWITCH, POWER, S102

53

C014024

1

PCB

54

C014379

1

RESISTOR NETWORK 9x4. 7K, SIP, R176

55

CA015325

2

LED & STANDOFF ASSEMBLY

810 SIDE BOARD
SOURCE: CA014162

2of 4 REV 10

ITEM

NO.

PART NUMBER QTY .

DESCRIPTION

1

C014179-08

1

2

21-101474

1

3

C014180-05

1

4

C014181-01

4

5

CO 14 180-08

1

6

C014181-02

1

7

C014181-03

3

8

CO 10 39 4

2

9

C014181-05

—

10

CO 14 39 2

2

11

C014368

2

12

C014780

3

13

14-51R1

1

34

14-5220

1

15

14-5101

5

16

14-5241

1

17

14-5331

1

18

14-5221

1

19

14-5751

1

20

14-5821

1

21

14-5102

5

22

14-5332

1

23

14-5202

1

24

14-5222

4

25

14-5392

1

26

14-5472

2

27

14-5752

1

28

14-5103

8

29

14-5105

1

30

15-5360

1

31

19-411504.

1

32

C014703

1

33

31-1N914

2

34

31-1N4001

5

35

C014398

4

36

34-2N3904

2

37

C014394

2

it

ii

it

MYLAR FILM:

II

II

CAP, CER, AXIAL: 82pf, 10%, COG, C159
MYLAR FILM ,47uf ,100V, 10%, C152

CE^AXJfAL; 220pf ,10%. X7R. C153

.OOluf, +$0-20^ , Z5U, C154-156 ,120
.0047uf, 20%, X7R, C157
. Oluf , +80-20%, Z5U, C147
.luf, +80-20%, Z5U, 0161,163,144
.22uf , 20%, 145,158

CER, AXIAL: ,22uf, ALTERN ATE FOR ITEM 8
ELECTROLYTIC: lOuf, 16V,+50-10%,'RADIAL,Cl43,160

470uf , 16V, +50-10%, RADIAL, C150,l
4700uf , 25V , +50-10%, RADIAL, C146,

C148,149

RESISTOR: 1.1 cbm, 1/4W, 5%, R139
22 ohm, 1/4W, 5%, R173
100 ohm, 1/4W, 5%, R138, 147, 174, 162, 163
240 ohm, 1/4W, 5%, R148
330 ohm, 1/4W, 5%, R146 '

220 ohm, 1/4W, 5%, R141
750 ohm, 1/4W, 5%, R170
820 ohm, 1/4W, 5%, R167
IK, 1/4W, 5%, R137, 149, 151, 154, 156,

3.3K, 1/ 4W, 5%, R155
2K, 1/4W, 5%, R150
2.2K, 1/4W, 5%, R159 , 160 , 171 , 145
3.9K, 1/4W, 5%, R161
4.7K, 1/4W, 5%, R164 , 168
7.5K, 1/4W, 5%, R169

10K, 1/4W, 5%, R140, 143, 152, 153, 157, 158, 165

166

1MEG, 1/4W, 5%, R144
36, 1/2W, 5%, R172
VARIABLE: 500K, R142
INDUCTOR: 680uhy, L103
DIODE: 1N914 , CR110,119
" 1N4001,CR109, 115-118

" MR501, CR111-114

TRANSISTOR: 2N3904, Q116,117
" MPSA06 , Q114 ,115

810 REAR BOARD

SOURCE: CA014161

lof 4 REV 12

8-8

ITEM

NO.

PART NUMBER QTY .

DESCRIPTION

38

CA015326

1

39

C015505

1

40

C014 386-01

1

41

C014386— 02

3

42

C014725

1

43

C014715

1

44

C012995

2

45

C014719-03

1

46

C014716-03

2

47

C014719-02

2

48

C014796

4

49

C014025

1

50

C014641-11

1

TRANSISTOR & HEATSINK ASSEMBLY

CAP, ELECTROLYTIC, RADIAL, 47uF, 16V, +50-10%

I.C. SOCKET: 8 PIN

I.C. SOCKET: 14 PIN

SWITCH, LOGIC, S101

CONNECTOR: POWER JACK,J110

” 13 PIN, RIGHT ANGLE, J107,108

" 23 PIN, J106

" 3 PIN, J104 , J105

" 5 PIN, J103,109

LATCHING FASTENER
PCB

PCB SERIAL NO. LABEL (SEE MFG. PROCEDURE)

810 REAR BOARD

SOURCE: CA014161

2of 4 REV 12

8-9

ITEM

NO.

PART NUMBER QTY .

DESCRIPTION

1 CA014161

2 C014332

3 C010174-XX

1 PCB SUB-ASSEMBLY

1 IC: LM311, A109

3 TRANSISTOR ARRAY, A107,110,lll

4 C014348

1 VOLTAGE REGULATOR, A108*

* Not listed on source CA014833

810 REAR BOARD

SOURCE: CA014833

2of 2 REV 1

1 CA014162 1

2 CO 11299 1

3 C014329 1

4 C010745 1

5 CO 10 750 1

6 C014328 1

7 C014334 2

8 CO 10447 1

9 C014333 1

10 C011465-XX 1

11 C010174-XX 1

12 C014136 1

13 C014137 1

14 72-CL605 2

15 C014138 1

16 C014641-10 1

PCB ASSEMBLY

IC: CUSTOM ROM, A102

IC: FLOPPY CONTROLLER - 1771, AIDS

IC: CUSTOM, A101

IC: CUSTOM, A104

IC: 6810, TRANSISTOR ARRAY, A103
IC: 4013 " " 2101,105

IC: 4077 " " Z104

IC: 4011 " " 2102

IC: 4069 " " 2103

IC: TRANSISTOR ARRAY A106
INSIDE COMPONENT R.F. SHIELD
OUTSIDE TRACE R.F. SHIELD
SCREW, #6x5/16 THD. F. PHIL. HD
GROUND BRACKET

PCB SERIAL NO. LABEL (SEE MFG. PROCEDURE)

810 SIDE BOARD

SOURCE: CA014834

2of 2 REV 3

8-10

APPENDIX

Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Appendix G

ATARI 810 Block Diagram

810 Side Board Schematic

810 Side Board Silkscreen

810 Rear Board Schematic

810 Rear Board Silkscreen

810 Wiring Harness Diagram (Alterna

ERROR Code Listing

9-1

9-2

A

9-3

CO 14334 CD40I3

DRIVE

MOTOR

WRITE

PROTECT

HEAD

I/O

STEPPER

MOTOR

'QOOIO

JI03

REAR BD.

'00000

JIOI

SIOE BO.

•QIQ00

(-) BLACK - 1
PHOTO-X3TR

(+)RED-

YELLOW

GREEN , —

v '

TACH. GEN.
OUTPUT (A.C.)

*- BLACK (-), wg>J
L.E.O. (ERASfcHEAO)

‘GREEN (+) r

(Vcc)

SHIELD-

BLUE

JI09

REAR BO.

•QQ000

BLACK - 1

(COMMON)

WHITE -

( PHASE I )

-white!/ r/w \

- BLACKJV HEAD/ 0

RED

(PHASE 2)

ALTERNATE WIRING HARNESS ARRANGEMENT

9-8

ERROR CODES

ERROR

ERROR

CODE ERROR CODE MESSAGE

CODE

ERROR CODE MESSAGE

2

Memory Insufficient

142

Serial Bus Data Frame Overrun

3

Value Error

143

Serial Bus Data Frame Checksum Error

4

Too Many Variables

144

Device Done Error

5

String Length Error

145

Read After Write Compare Error

6

Out of Data Error

146

Function not Implemented

7

Number Greater then 32767

147

Insufficient RAM

8

INPUT Statement Error

160

Drive Number Error

9

Array or String DIM Error

161

Too Many OPEN Files

10

Argument Stack Overflow

162

Disk Full

11

Floating Point Overflow/

163

Unrecoverable System Data I/O Error

Underflow Error

164

File Number Mismatch

12

Line Not Found

165

File Name Error

13

No Matching FOR Statement

166

POINT Data Length Error

14

Line Too Long Error

167

File Locked

15

GOSUB or FOR Line Deleted

168

Command Invalid

16

RETURN Error

169

Directory Full

17

Garbage Error

170

File Not Found

18

Invalid String Character

171

POINT Invalid

NOTE: The following are INPUT/OUTPUT

errors that result during the use of
disk drives, printers, or other acces-
sory devices. Further information is
provided with the auxiliary hardware.

19 LOAD Program Too Long

20 Device Number Larger

21 LOAD File Error

128 BREAK Abort

129 IOCB

130 Nonexistent Device

131 IOCB Write Only

132 Invalid Command

133 Device or File not Open

134 BAD IOCB Number

135 IOCB Read Only Error

136 EOF

137 Truncated Record

138 Device Timeout

139 Device NAK

140 Serial Bus

141 Cursor Out of Range

9-9

9-10

INDEX

10-1

10-2

INDEX

A108 (VOLTAGE REGULATOR)

ADJUSTMENTS, ALIGNMENTS

APPENDIX

BASEPLATE

BLOCK DIAGRAM

BOOTING TEST

BUSY LITE

CARRIER ASSEMBLY

CASE, DISK DRIVE

CAT'S -EYE PATTERN

CLEANING PROCEDURE

CLOCK CIRCUITRY

COMPATABILITY TEST

CYCLIC REDUNDANCY CHECKS

DATA GATE

DATA I/O & MANIPULATION
DATA INTERFACE
DEMAGNETIZATION
DIFFERENTIAL AMP
DIFFERENTIATOR
DISASSEMBLY

DISASSEMBLY FLOW CHART
DISASSEMBLY/REASSEMBLY
DISK DRIVE SELECT
DISK ROTATION
DISKETTE

DISKETTE DRIVE MOTOR & LOGIC
DOS

DRIVE BELT

DRIVE BELT ADJUSTMENT
DRIVE MOTOR

6- 13,46

7- 1
9-1

6-6,54

3- 3, 4, 6/9-3

4- 4
2-18
6-38

6- 5,56

7- 7,8
7-3
2-9
4-9

2-11,25

2 - 11,12

2-4,5

2-4,10

7-3

2-13,15

2-13,15

6-5

6-4

6-1,3

2-19

2-23

2-23,24

2-4,18

4-7

6- 14,45/7-13,14

7- 13
6-15,44

10-3

INDEX

ERASE DRIVER
ERASE HEAD
ERROR CODES

FLOPPY DISK CONTROLLER

FLYWHEEL

FORMATTING

FORMATTING TEST

HEAD ASSEMBLY

HIGH LEVEL DRIVE

LOW LEVEL DRIVE

MPU

PARTS LISTS
PCB , REAR
PCB , SIDE
PIA

POWER SUPPLY
POWER UP LOGIC CIRCUIT
PULSE REGENERATOR
Q113 (TRANSISTOR)

QUICKCHECK

RADIAL TRACK ALIGNMENT
RAM

REASSEMBLY

READ DATA CONDITIONING CIRCUITRY
READ OPERATION
READ/WRITE & ERASE HEADS
READ/WRITE & ERASE HEAD CLEANING
& DEMAGNETIZATION
RF SHIELD
ROM

SCHEMATIC, REAR BOARD
SCHEMATIC, SIDE BOARD

2-12

2-4

9-9

2 - 10,12

6-18,19,37,38

2-23,24

4-6

6-21,31

2 - 11,12

2 - 11,12

2-7

8-1

6-12,48

6-8,52

2-6

2-4,20

2-9

2-15

6- 13,46
4-1

7- 5
2-7
6-26
2-13
2-22
2-4,21

7-3

6-10,51

2- 7

3- 7/9-6
3-5/9-4

10-4

INDEX

SETUP

4-4

SIGNAL GATE

2-13

SILKSCREEN, REAR BOARD

9-7

SILKSCREEN, SIDE BOARD

9-5

SPECIFICATIONS

1-3

SPEED ADJUSTMENT

7-5,10

SPINDLE, DRIVE

6-18,19,37,38

SPINDLE SHAFT BEARINGS

6-20,36

STEPPER MOTOR

6-24,27

STEPPER MOTOR & LOGIC

2-4,17

SYMMETRY AMP

2-13

THEORY OF OPERATION

2-1

TIME DOMAIN FILTER

2-13,15

TRACK 00 STOP ADJUSTMENT

7-11

TRANSPORT, DRIVE

6-11,49

TRANSPORT FLYWHEEL/DRIVE SPINDLE

6-18,37

TROUBLESHOOTING GUIDE

5-1

VCC/RDY SIGNAL

2-5

VOLTAGE REGULATOR (A108)

6-13,46

WIRING HARNESS

6-53/9-8

WRITE DRIVER

2-11

WRITE & ERASE GATE

2-12

WRITE & ERASE LOGIC CIRCUITRY

2-10,11

WRITE OPERATION

2-21

WRITE PROTECT CIRCUIT

2-16

WRITE PROTECT TEST

4-5

WRITE PROTECT WIRING HARNESS

6-8

WRITE VERIFICATION

4-7

ZERO CROSSING DETECTOR

2-13,15

10-5

10-6

NOTES